This invention relates to portable toilets and is particulary concerned with a vent arrangement for the flush water storage tank that allows air into the tank to replace water removed from flushing but which also prevents water leakage through the vent in case of splashing of water in the tank or overturning of the toilet.
A number of commonly assigned patents disclose portable toilets of the type which comprise a holding tank section and a seat section separately mounted on the holding tank section. The seat section comprises a bowl with a bottom outlet which registers with an opening in the top wall of the holding tank. When the two sections are mounted together the bowl outlet is in sealed relationship with the opening in the top wall of the holding tank. A valve in the holding tank is disposed at the opening and when the valve is opened the contents of the bowl drop into the holding tank whereby the accumulated contents may be dumped form time to time at suitable sanitary disposable stations.
The seat section has a hollow wall structure serving as a water storage compartment for flushing purposes with the rear of the section including a fill port for filling the compartment and a pump such as a manually operable bellows for flushing the bowl. The pump operates on a pressure differential in that downward movement discharges flush water from the tank onto the bowl and upward movement lowers the pressure to draw water upwardly from the tank. Thus withdrawal of water from the flush tank for flushing purposes requires adequate air venting of the tank so that each water withdrawal can be replace by air. However, it is also desirable to prevent leakage of water from the tank through the air vent when the toilet is overturned or when water in the tank is splashing due to movement of the toilet.
In accord with this invention, a vent opening is provided in the cap for the fill opening so that atmospheric air can at all times flow freely into the interior of the storage tank during flushing. A vent chamber is formed integrally with the fill cap at a position within the tank. A seal member is arranged within the vent chamber so that if the toilet is tilted or moved so that flush water in the tank is caused to splash or if the toilet is inadvertently overturned water from the flush tank will not spill outwardly through the vent opening because the seal will be moved by water in the tank to cover the vent opening. Otherwise air can freely pass between the atmosphere and the tank interior, to provide a continuous vent for flushing, thermal expansion, altitude changes, etc.
The foregoing features, advantages and benefits of the invention along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings.